The proposed research will investigate the perception of tactile patterns by human subjects. Of particular concern are the spatial aspects of tactile stimulation and the ways in which spatial information is encoded. The proposed research consists of three projects. Project 1 will use a newly-developed stimulator, a dense array, to examine several aspects of spatial pattern perception The stimulator consists of a 20 by 20 array of independently-controlled drivers. The center-to-center spacing for the drivers can be varied from 0.4 mm to 1.0 mm. The dense array will be used to selectively activate different cutaneous receptor populations and to examine spatial sensitivity and pattern resolution on the fingerpad and palm. The dense array will also be used to investigate the possibility of simulating tactile experiences such as roughness. The second project will focus on the ability of subjects to selectively attend to a target stimulus presented at one location on the skin and ignore nontarget stimuli presented at other spatial locations. The effect on selective attention of such variables as the distance between target and nontarget stimuli, the nature of the target and nontarget patterns, and the receptor populations activated by the stimuli will be examined. In addition, the effects of the spatial orientation of the site being stimulated and concurrent kinesthetic stimulation will be measured. The third project will examine spatial localization of tactile stimuli. Both the way in which spatial pattern identification becomes dissociated from the location of stimulation and the way in which localization accuracy changes with stimulus conditions will be measured. The possibility of altering spatial sensitivity through prolonged stimulation will be examined. The prolonged stimulation will be provided by stimulators worn on the arm and by the dense array. The results of the proposed research will be compared to studies with visual and auditory stimuli. The results should be relevant to the development of cutaneous communication systems for the deaf, blind, and deaf-blind and to the measurement and understanding of neurological problem